1. Temperature-dependent deformation processes in two-phase TiAl + Ti3Al nano-polycrystalline alloys.
- Author
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Li, Pengtao, Yang, Y.Q., Koval, Vladimir, Chen, Jianxin, Luo, Xian, Zhang, Wen, Wang, Bowen, and Yan, Haixue
- Subjects
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DEFORMATIONS (Mechanics) , *MATERIAL plasticity , *ALLOYS , *DYNAMIC simulation , *HIGH temperatures , *POLYCRYSTALLINE semiconductors - Abstract
Although deformation processes in single-phase nano-polycrystalline alloys at different temperatures are well described, the deformation mechanism in two-phase nano-polycrystalline alloys at different temperatures is still unclear. Here, the deformation behaviour of the two-phase TiAl+Ti 3 Al nano-polycrystalline alloys is investigated at different temperatures by molecular dynamic simulation. For a comprehensive understanding of the processes, mechanical properties of the single-phase TiAl and Ti 3 Al nano-polycrystalline alloys are explored as well. The results of numerical simulations indicate that temperature has a strong influence on the deformation mechanism of the alloys. When temperature is below 800 K, the critical grain size (~8.3 nm) becomes a dominant factor controlling the deformation process in the single-phase TiAl. In the two-phase TiAl+Ti 3 Al nano-polycrystalline alloys, the motion of dislocations in the TiAl phase with the grain size smaller than the critical size dominates the deformation process. On the other hand, no obvious phenomena linked with the critical size occur in the Ti 3 Al phase. Once the strain exceeds 18.0%, the dislocation emission is observed in the Ti 3 Al grains. At high temperatures (≥800 K), in the two-phase nano-polycrystalline alloy, the deformation mechanism changes from the plastic deformation to the boundary slip and recrystallization. Unlabelled Image • Deformation behaviour of two-phase TiAl+Ti 3 Al nanopolycrystalline alloys is described using molecular dynamic simulations. • The displacement of dislocations in TiAl grains smaller than ~ 8.3 nm dominates the deformation processes below 800 K. • The deformation mechanism changes from the plastic deformation (< 800 K) to the boundary slip and recrystallization at 800 K. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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